Method of and means for electric voltage regulation



April 25, 1933. HARZ 1,906,210

METHOD OF AND MEANS FOR ELECTRIC VOLTAGE REGULATION Filed March 19, 1931 2 Sheets-Sheet 1 1H VEN TOR Hermann Harz HTTORHEY April 25, 1933. R 1,906,210

METHOD OF AND MEANS FOR ELECTRIC VOLTAGE REGULATION Filed March 19, 1931 2 Sheets-Sheet 2 Big. 4 133. 5.

INVENTOR H rmann Harz BY Z v E:

FITTORNEY Patented Apr. 25, 1933 UNITED STATES PATENT OFFIC PATENTS CORPORATION, OF

NEW YORK, N. Y., A CORPORATION OF NEW YORK METHOD OF AND MEANS FOR ELECTRIC VOLTAGE REGULATION Application filed March 19, 1981, Serial No. 523,675, and in Germany July 23, 1829.

My invention relates to a method of and means for electric voltage regulation and more particularly to transformer systems with variable secondary or output voltage, and methods of operating such regulators.

A main object of my invention is to provide a transformer system which allows a continuous control of secondary voltage with infinitely small increments from zero to the maximum value.

Another object of my invention is to provide a transformer system with continuously variable voltage control, which utilizes apparatus of standard equipment making it unnecessary to employ special apparatus such as tap transformers and the ike, as hitherto used in the art.

A further object of my invention is to provide means for using a polyphase induction regulator in connection with a voltage transformer arrangement for supplying a continuously variable output voltage from zero to maximum value.

These and further objects as well as advantages of my invention will become more apparent from the following detailed description, taken with reference to the accompanying drawings, in which I have illustrated, by way of example, some circuit diagrams in which my invention is embodied. I wish it to be understood, however, that the description and the exemplifications shown by the drawings should be regarded as being illustrative only of the broader principle and scope of the invention, such as expressed by the appended claims.

Figure 1 of the drawings illustrates one example of voltage transformer arrangement comprising two stationary transformers, and an induction regulator of standard this system being especially adapted for operation in high tension power systems.

Figure 2 illustrates a similar arrangement using only a single stationary transformer and induction regulator of standard type with a transformation ratio of 1: 1.

Figure 3 is a vector diagram explaining the theoretical operation of the invention.

Figure 4 is a similar system to Figure 2 for a different. transformation ratio from 1: 1.

Figure 5 represents a further modification of the systems according to Figures 2 and 4, especially adapted for work for operation in high tension systems.

Similar reference characters identify similar parts throughout the dilierent views of the drawings.

The novel idea underlying the invention in its broadest terms and aspects may be expressed to consist in the provision of 'at least two, substantially separate magnetic circuits determining in their resultant effect the value of the output voltage and being provided with means for continuously shifting the time phase osition of the alternating magnetic flux oi the alternating magnetic flux of the other circuit. In the preferred embodiment of the invention, as illustrated in the drawin s, I use a multi-phase induction regulator f or producing the phase shift of the magnetic flux, which, as is well known, has the advantage of being operated without opening the circuit or without short-circuit-ing any transformer coil and therefore gives no trouble from arcing at the switch contacts, such as is the case with the ordinary step-by-step or variable ratio potential regulators commonly used in the art for supplying variable output voltage of a transformer.

As is well known, a polyphase induction regulator in every essential detail is a polyphase induction motor, the polyphase C011- wound rotor of which can be rotated and locked in any position desired. The primary windings of such a regulator in the ordinary uses are connected across the supply lines in the same manner as the ordinary windings of a polyphase induction motor, and the secondary windings, instead of being closed upon themselves, as is true of the secondary windings of an induction motor, are separately insulated and separately connected in series in the delivery circuits from the regulator. In such apparatus, the polyphase electro-motive force in each secondar coil is of the same frequenc as the primary electro-motive force. an its value is enone circuit in respect to tirely independent of the mechanical position of the secondary winding in respect to the primary winding. However, the time phase position of the secondary electro-motive force varies directly with the electrical space position of the movable or secondary member in such a manner that the resultant electro-mot-ive force delivered is the vector sum of, or difference between the primary and secondary electro-motive forces and is not constant but varies largely with the osition of the movable or secondary winding. This particular property of a multiphase induction regulator, of merely changing its time position when the relative position between primary and secondary member is varied, has made the application in ractice a rather limited one, such as for Boosting up the line voltage to compensate for the voltage drop in a transmission line. According to the novel features of the resent invention, an induction regulator o the type as referred to may be used for continuously varying and controlling the secondary voltage as to its effective value between zero and maximum limit.

Referring to Figure 1 of the drawings, I have shown at 1, 2, 3 a three-phase power line and a voltage transformer system, comprising two stationary three-phase transformers 4 and 6 of the standard type, such as, for instance, of the well known core type. and a three-phase induction regulator 5. Each of the transformers 4 and 6 has primary windings 7, 8, 9 and 16, 17 and 18 respectively; secondary windings 10, 11, 12 and 19, 20, 21 respectively, and furthermore, tertiary windings 13, 14, 15 and 22, 23, 24 respectively. The induction regulator 5 includes, in the usual manner, a stationary member carrying a three phase winding with phases 25, 26 and 27, and a secondary movable member with a three-phase winding, comprising phases 28, 29 and 30, as shown. 31, 32 and 33 represent the open terminals of the primary windings, which in the example shown are connected in star fashion, the star, or zero point, having been shown at 41. 34, 35 and 36 represent the open terminals of the secondary or rotatable winding of the induction regulator also connected in star fashion, with its star or neutral point at 42. The secondary or rotatable member of the induction regulator may be rotated in respect to the primary or stationary member by means of a suitable drive indicated at 40, such as a hand wheel or worm gear drive. I have furthermore shown at 37, 38 and 39 the secondary or output termains of the system, to which a consuming or delivery circuit is to be connected. The connection of the individual windings of the transformer and the induction regulator is as follows, referring in particular to the phase 1 of the system.

for the secondary, the output terminal it phase winding 1 being at 39. The tertiary windings l3 and 22 of the transformers 1 and 6 are connected each to a corresponding phase windin of the induction regulator.

In the examp e shown, the tertiary wind- 5 ing 13 of transformer 1 is connected to the primary winding 25 of the induction regulator and the tertiary winding 16 of the transformer 6 is connected to the cooperating secondary and rotatable winding 28 of the induction regulaton' The windings of the second and third phase of the system are connected in an identical manner to the windings belonging to phase 1, as is seen from the circuit diagram. The windings are designed in such a manner that equal voltages are generated in the windings 7, 8, 9 and 16, 17, 18. Furthermore, in the secondary windings 10, 11, 12 and 19, 20, 21, and also in the system comprised of windings 13, 14, 15 and 25, 26, 27, and 22, 23, 24 and 28, 29, 30. This is easily obtained by properly choosing the number of effective turns for the individual windings. In the example, all the windings, primary, secondary and tertiary, are shown connected in star fashion. It is, however, understood that any other connection could be used, such as delta or -mixed connection, for all the windings or partially, without de arting from the spirit of the invention. he windings may also be arranged concentrically in the customary manner, upon the iron cores, in place of the side-by-side arrangement, as shown for purposes of clearer illustration.

Referring to phase 1 of the system, it is seen that the voltages existing at the terminals of the windings 13 and 25 must possess equal time phase position in such a manner that by a displacement of the winding 28 in respect to winding 25, producing a change in the time phase position of the latter winding, a corresponding change in time phase position is of necessity forced upon the winding 13. Accordingly, the time phase position of the magnetic flux in the transformer core is varied and a relative displacement of the magnetic flux in the two transformers is obtained. Thus, a gradm The secondary windings of: the

Lab

operating vector diagram, according to Figure 3.

Referring to Figure 2, I have illustrated a transformer system utilizing only a single stationary transformer and induction regulator. I have again shown at 1, 2, 3 the phases of a three-phasefpower line, a threephase transformer 43 0 standard construction, and a three-phase induction re ulator 44 connected in series to the line. n this particular case, the transformer 43 carries only two windings, one primary and one secondary windin for each phase 45'and 46, 47 and 48, an 49 and 50 respectively. I have again shown at 37, 38, 39 the secondary output terminals for supplying a continuously controllable output Volta e from zero to a maximum value. The in action regulator 44 is again comprised of a primary and stationary member provided with windings 51, 52 and 53, and a secondary and rotatable member carrying windings 54, 55 and 56. The secondary windings of the induction regulator are again arranged in star connection with the star or zero point shown at 57. The primary windings 51, 52 and 53 are left open and are connected with the windings of the stationary transformer in the following manner, referring in particular to the phase 1 of the system. The input terminals of the several windings have been designated by B and the output terminals of the windings by E. In the present case, it is assumed that all of the windings have the same number of turns and their connection is as follows: Input terminal of primary winding 45 is connected to phase 1 of the power line and its output terminal is connected, on the one hand to the input of winding 54, and on the other hand, to the output of winding 46. Furthermore, the primary winding 51 of the induction regulator is connected in parallel relationship to the primary 45 of the transformer, that is; input is connected with input, and output is connected with output. In the zero position of the induction regulator, that is; when the mutual inductance of its primary and secondary windings 51 and 54 is a maximum (axial position), the line voltage 05, referring to Figure 3, is comprised of the drop 0a,, through the winding 54 and the drop a b throu h the shunted windings 51 and 45. The win ing 46, on account of its being wound in opposite sense in respect to winding 45, produces the opposite voltage a c Therefore, the sum of the voltages of 54 and 46 will appear between 57 and 39, which is equal to the sum of 0a, plus a 0 which sum in the zero position, as assumed, is equal to zero. If, however, winding 54 is rotated in respect to winding 51 to the amount of angle a in one direction, the line voltage will be distributed upon the windin s of the induction regulator according to t e triangle owb.

The resultant effective number of winding turns upon which the primary volta e is impressed is decreased accordingly, an the flux in both transformers increases. The drop through winding 54 will then .be equal to ca displaced in respect to the voltage 0a by the angle a in one direction, and the dro through winding 51 will be equal to a displaced by the same angle in the opposite direction. As the winding 51 is connected in parallel to the winding 45, it will force upon it the same voltage. In winding 46 this voltage will appear in a reverse sense as are, and if added accordingly to the Volta e co (under an angle of 2 a) the resultant voItage will be 00 that is; equal to the sum of 0a and am. As may be readily seen from the diagram, this voltage 00, corresponding to the output voltage delivered by the system at 39, does not change its phase angle dependent upon the changes of the angle a of rotation of the movable member of the induction regulator in respect to its stationary member. The output voltage 00 will only change its value and in the event that the induction regulator is rotated in the opposite direction from its zero position, it will also change its direction. At an angle of rotation of 45 from the zero position, the secondary voltage 00 will assume a value equal to the primary voltage, in the event of a transformation ratio 1: 1, as assumed in this example, and when the angle of rotation is further increased, the change of magnetic flux will be excessive. For this reason, values of displacement over 45 are not used ordinarily for practical purposes.

It is obvious that the circuits as described are subject to many modifications comprising at least two transformers substantially independent of each other, one of which is provided with means for varying the relative time phase position between the primary and secondary currents. The transformers are inter-connected in such a manner that the output voltage is determined by the resultant change of the magnetic flux components of the transformers in sucha manner that by varying the relative time phase position resulting from variations in relative time phase position between primary and secondary currents of one of the transformers, a gradual change of the output voltage is obtained. For polyphase operation, preferably an induction regulator is used as a transformer for varying the relative time phase position between its primary and secondary currents.

Referring to Figure 4, this illustrates an arrangement similar to Figure 2, with additional improvements for using a different transformation ratio from 1:1 in the 45 position of the induction regulator. According to Figure 4, the ends of windings 45 and 46 are not directly connected, but

are connected to the secondary 54 of the induction regulator to provide an auto-transformer arrangement, whereby a secondary output voltage either lower or higher than the primary or input voltage is obtained. The secondaries 54, 55, 56 of the induction regulator are provided with suitable taps 61, 62 and 63 respectively. The primary windings of the transformer and induction regulator are again connected in parallel in a way similar to that shown in Figure 2. The end of the primarywinding 45 is furthermore connected to the tap 61 of the secondary 54 of the induction regulator and the end of the secondary winding 46 of the transformer is connected in the example shown, to the beginning of the secondary 54 of the induction regulator. The windings are again designed in such a manner that similar voltages are produced in 45, 51 and 54 (between 57 and 61) and furthermore in 54 (between 57 and B) and 46. The other phases are connected in an analogous way, as illustrated. In the particular example shown, the auto-transformer arrangement is such that the secondary voltage is higher than the primary voltage, that is; the system acts as a step-up transformer. If it is desired to provide a secondary voltage lower than the primary voltage or to use a step-down transformer system, the connections of 61 and B of winding 54 must be exchanged in such a manner that, at the same time, the number of winding turns 54 and 46 are properly chosen so that the voltage between 57 and 61 is equal to the voltage at 46 and the voltage between 57 and B is equal to the voltage at 45. The secondary voltage in these arrangements is shown in the diagramFigure 3-to consist of the sum oa c in the case of a step-down arrangement or 04x 0 in the case of a step-up arrangement. As is obvious, it is also possible to provide two separate windings in place of an auto-transformer arrangement, as illustrated.

In many cases, it is preferable to entirely insulate the movable member of the induction regulator from the primary or net-work voltage. A system of this kind is illustrated in Figure 5. The arrangement of the windings of the induction regulator in this case is reversed, in that the secondary winding 54 of the induction regulator connected in series with windings 45 and 46 of the transformer 43, is arranged on the stationary member of the induction regulator 44 and the primary 51 is arranged on the rotatable member. Winding 51 and a further tertiary winding 64 of the transformer 43 are connected to form a separate circuit, insulated from the remaining parts of the system and serving to produce the voltage regulation. Both windings have an equal number of turns and may be designed for any voltage desired. It is also possible to have part of the windings 45 and 46 coincide with the winding 64 or use an autotransformer arran enient for the winding 54, as above descri ed, for step-up or stepdown transformation, or to use two separate windings. The remaining phases havin tertiary windings 65 and 66 are connected in a similar manner to phase 1, as described. The operation of this arrangement, as is evident, is similar to that according to F igure 2, in that the displacement of the rotatable windings of the induction regulator will have the effect of producing a proportionate displacement of the flux in the transformer cores and produce a corresponding variation of the output voltage.

Although the invention has been described with reference to the showin of the drawings, it is obvious that it is subject to many modifications, all coming within its broad and comprehensive scope, as set forth in the claims.

\Vhat I claim is:

1. In a voltage transformer operated from a substantially constant input voltage and having means for producin at least two magnetic flux components, etermining in their resultant effects the value of the output voltage, the method of continuously controlling the output voltage consisting in var ing the relative time phase position of said magnetic flux components.

2. In a voltage transformer comprising means forming a plurality of magnetic circuits, primary and secondary windings interlinked with said circuits for producing a corresponding number of magnetic flux components through said magnetic circuits, connections between said primary and said secondary windings whereby the transformer output voltage is determined by the resultant of said flux components, and means for varying the relative time phase position of said flux components.

3. In a voltage transformer system comprising means forming at least two substantially independent magnetic circuits, primary and secondary windings interlinked with said circuits, connections between said primary and said secondary windings where y the transformer output voltage is determined by the resultant vector effect of the flux components of said magnetic circuits, and means for varying the electric time phase position between a primary and a secondary winding of one of said magnetic circuits for roducing corresponding variations in the re ative time phase position of said magnetic flux components for continuously varying the output voltage of said transformer system between zero and maximum value.

4. In a voltage transformer system comprising at least two substantially separate transformers, primary and seconda windings for said transformers, connect1ons between said primary and secondary windings whereby the output voltage is determined by the resultant effect of the magnetic flux components of said transformers, and means for varying the relative time phase position of said flux components of said transformers.

5. In a voltage transformer system comprising at least two substantially independent transformers, primary and secondary windings for said transformers, connections between said primary windings and said secondary windings whereby the output voltage is determined by the resultant vector effect of the magnetic flux components of both of said transformers, and means for varying the relative time phase position of primary and secondary windings of one of said transformers for producing-a proportionate variation of the relative time phaseposition of the magnetic flux components of said transformers.

6. In a voltage transformer system comprising at least two substantially independent transformers, primary and secondary windings for said transformers, connections between said. primary windings and said secondary windings whereby the output volt- .ageis determined by the vector difference of the magnetic flux components of said transformers, means for varying the relative time phase position between a primary and secondary winding of one of said transformers for producing a proportionate variation of the relative time phase position of said magnetic flux components for continuously varying the output voltage between zero and maximum value.

7. Ina polyphase voltage transformer system comprising at least one polyphase transformer, a polyphase induction regulator, said transformer and said regulator being provided with primary windings and secondary windings, and connections between said primary windings and said secondary windings whereby the output voltage is determined by the resultant vector effect of the magnetic flux components of said transformer and said induction regulator, and

means for varying the relative time phase tor, said transformer and said regulator be ing provided with primary windings and secondary windings, connections between said primary wlndings and said secondary windings whereby the transformer out ut voltage is determined by the vector di erence of the magnetic flux components of said transformer and said induction regulator respectively, and means for relatively displacing the primary and secondary windings of said induction regulator for producing proportionate variations of the relative tions between the beginnings and the ends of said primary windings, respectively, further connections from the end of said primary winding of said stationary transformer to the end of the secondary winding of said stationary transformer and to a point on the secondary winding of said induction regulator, and means for displacing the secondar winding of said induction regulator relatlve toits primary winding.

10. In a polyphase transformer system comprising at least one polyphase stationary transformer havin primary and secondary windings, a polyp ase induction regulator having stationary and rota windings, connections between correspon ing phase windings of said stationary transformer and said induction regulator whereby .the primary windings are connected substantially in series, the secondary output voltage being determined b the vector difference of the secondary v0 tages of the secondary windings of the stationary transformer and the induction regulator and means for displacing the secondary winding of said induction regulator relative to its primary winding.

11. In a voltage transformer system as described in claim 10, in which primary and secondary windings of said stationary transformer and of said induction regulator have an equal number of winding turns.

12. In a voltage transformer system as described in claim 10 in which a different ratio between primary and secondary windings of said stationary transformer is provided whereby the primary winding of said stationary transformer is connected to a tap point on the secondary winding of said induction regulator.

13. In a polyphase voltage transformer system comprising at least one polyphase transformer having a primary, secondary and a tertiary winding, a polyphase induction regulator, stationary and rotatable windings of said induction regulator, connections from said tertiary winding of said stationary transformer to one of the windings of said induction regulator, the remaining winding of said inductionv regu at r being connected in series with both of said rimary and secondary windings of said stationary transformer, and means for continuously displacing said rotatable winding of said induction regulator relative to its stationary winding. 14. In a polyphase volta e transformer system comprising a polyp ase stationary transformer having primary, secondary and tertiary windings, a polyphase induction regulator having a primary rotatable winding and a secondary stationary winding, connections from said tertiary winding of said stationary transformer to the secondar winding of said induction regulator, the pne mary winding of said induction regulator being connected in series with both of said primary and secondary windings in said stationary transformer, and means for continuously displacing said rotatable winding of said induction regulator relative to its stationar winding. 15. a polyphase voltage transformer system comprising ,two polyphase stationary transformers having primary, secondary and tertiary windings, 'a polyphase induction regulator having a olyphase stationary and a polyphase rotata le winding, connections between the primary windings of said transformer whereby said primary windings are connected substantially in series, further connections between the secondary windings of said transformer whereby said secondary windings are also connected in series in opposite sense as compared to said primary windings, further connections from the ter- -tiary winding of one of said transformers to one of the windings of said induction regulator, and connections from the tertiary winding of the remaining transformer to the remaining winding of said induction regulator and means for continuously varyin the position of the movable winding of sai induction regulator relative to its stationary winding.

In testimony whereof I aflix my signature.

HERMANN HARZ. 

